{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-126360",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-11-10T21:12:01.228Z",
        "datePublished": "2026-11-12T22:24:22.023Z",
        "dateUpdated": "2026-11-12T22:24:22.023Z"
    },
    "containers": {
        "cna": {
            "title": "OpenTelemetry Python: Denial of service through quadratic-time traceparent parsing in opentelemetry-api",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1333",
                            "lang": "en",
                            "description": "CWE-1333: Inefficient Regular Expression Complexity",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "LOW",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/open-telemetry/opentelemetry-python/security/advisories/GHSA-mf5v-w3w3-f6cg",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/open-telemetry/opentelemetry-python/security/advisories/GHSA-mf5v-w3w3-f6cg"
                },
                {
                    "name": "https://github.com/open-telemetry/opentelemetry-python/pull/5818",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/open-telemetry/opentelemetry-python/pull/5818"
                },
                {
                    "name": "https://github.com/open-telemetry/opentelemetry-python/pull/5856",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/open-telemetry/opentelemetry-python/pull/5856"
                },
                {
                    "name": "https://github.com/open-telemetry/opentelemetry-python/commit/78123a2755c907c602e02352aebed4be86aa5350",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/open-telemetry/opentelemetry-python/commit/78123a2755c907c602e02352aebed4be86aa5350"
                },
                {
                    "name": "https://github.com/open-telemetry/opentelemetry-python/commit/faa72dae511ae64a7bf8ca63eff9ad4387d0b939",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/open-telemetry/opentelemetry-python/commit/faa72dae511ae64a7bf8ca63eff9ad4387d0b939"
                },
                {
                    "name": "https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.45.2",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.45.2"
                }
            ],
            "affected": [
                {
                    "vendor": "open-telemetry",
                    "product": "opentelemetry-python",
                    "versions": [
                        {
                            "version": "< 1.45.2",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-11-12T22:24:22.023Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "OpenTelemetry Python provides the Python API and SDK for OpenTelemetry. Prior to 1.45.2, TraceContextTextMapPropagator.extract() in opentelemetry-api can perform quadratic-time regular-expression backtracking on a malformed traceparent value containing a trace-context prefix, a long whitespace sequence, and an embedded newline. Exploitation requires an attacker-controlled carrier that preserves embedded newlines and permits a sufficiently large value, because conforming HTTP header values cannot contain embedded newlines. JSON-based carriers, including applicable MCP request metadata integrations, can preserve the required newline depending on the SDK, instrumentation, and message-size limits. Parsing on an asynchronous server's event-loop thread can consume excessive CPU and delay unrelated requests, while the advisory does not establish disclosure, modification, or code execution. This issue is fixed in version 1.45.2."
                }
            ],
            "source": {
                "advisory": "GHSA-mf5v-w3w3-f6cg",
                "discovery": "UNKNOWN"
            }
        }
    }
}